This White Paper is divided into two parts. Part I: U.S. Census Bureau Affordability and Income Indicators, which have received little attention in previous research regarding historic districts and affordable housing, even though these indicators are considered apropos. Reasons for their previous exclusion may include: (1) difficulties with finding a unit of analysis that can adequately measure change within historic districts, (2) an apparent lack of consistent and comparable longitudinal data for relevant measures, (3) the challenge of matching historic district boundaries to the geographic boundaries available from the U.S. Census Bureau, and (4) finding adequate comparison geographies amidst New York City’s varied real estate market.